Field of the Invention
The teachings in accordance with exemplary and non-limiting embodiments of this invention relate generally to a swiveling actuator configured to change a rotational power to a rectilinear motion and output the rectilinear motion.
Description of Related Art
This section provides background information related to the present disclosure, which is not necessarily prior art.
Generally, a motor outputs a rotational force generated by rotation of a rotor about a shaft in response to an electromagnetic interaction between the rotor and a stator. The power outputted by the motor is a rotational force, so that it is possible to move a mechanism to a desired direction using the rotational force.
Meantime, in order to move a mechanism for a rectilinear motion instead of rotation, a power transmission unit is needed to change a rotational motion to a rectilinear motion. The power transmission unit capable of changing the rotational motion to the rectilinear motion may include a crank, a lead screw shaft, a swiveling actuator and the like. The swivel(ing) actuator among these power transmission units may be used for multiple purposes, and is recently applied to a variable head lamp configured to obtain a maximum night view for a driver in conjunction with a steering direction of the driver.
As one of prior art, Korean Patent Laid-Open No. 10-2010-0037363 (opened on Apr. 9, 2010) discloses a swivel actuator applied to the variable head lamp, in which a nut member gear-coupled to a lead screw rotating by receiving a driving force of a motor reciprocates in conjunction with rotation of the lead screw, and a link member connected to an upper coupling lug of the nut member horizontally reciprocates to horizontally change an irradiation direction of a head lamp.
However, the swivel actuator thus configured suffers from disadvantages in that a connection area of the link member connected to a lug prevents generation of a gap by way of press-fitting, such that a load and a noise are generated on the swivel actuator to increase friction during repetitive operation.
Another disadvantage is that a step power loss of a driving motor provided in the form of a stepping motor may be generated during a process of changing a rectilinear motion of the nut member to a rotational motion, and legibility of luminous intensity (allowing light irradiated from a head lamp to accurately reach a driving path requiring an illumination by a driver) may deteriorate, in a case a gap is generated by dimensional instability.